Supportive Care (Part 1) Flashcards
Causes of constipation
- Disease-related
- Immobility
- IO
- low-residue diet, decreased food intake (not enough fibre) - Biochemical
- Hyperkalemia
- Hypercalcemia - Fluid depletion
- Reduced fluid intake
- Increased fluid loss
Complications of constipation include:
- Colic
- Confusion or restlessness
- Intestinal obstruction
What must you do before administering laxatives?
- check for intestinal obstruction
- consider underlying causes (hypercalcemia, drugs)
What are the different classes of constipation drugs?
- Bulk forming laxatives
- fybogel, metamucil - Stimulant laxatives
- Senna, bisacodyl - Osmotic laxatives
- Lactulose, PEG, phosphate enema, Forlax
Bulk forming laxatives:
- names of drugs
- MOA
- precautions/advice
- side effects
- fybogel, metamucil
- retain intraluminal fluid, softening faeces and stimulating peristalsis.
- patients must drink a lot of water, cannot take if they have intestinal obstruction
- colic, flatulence, unpalatable
Stimulant laxatives:
- names of drugs
- MOA
- precautions/advice
- side effects
- senna, bisacodyl
- directly irritate the smooth muscle of the small intestine, alter the water and electrolyte balance in the body such that there is a net retention.
- cannot take if your intestine is completely obstructed.
- side effects include: colic, flatulence, electrolyte imbalance.
Osmotic laxatives:
- names of drugs
- MOA
- precautions/advice
- side effects
- Lactulose, forlax, PEG, phosphate enema
- Draws fluid into the bowel via osmosis, to soften faeces and stimulate peristalsis.
- Patients must drink extra fluids.
- colic, flatulence, electrolyte imbalance, dehydration
rectum impaired, stool hard
- administer glycerin suppositories OR olive oil enema, followed by phosphate enema.
- Once disimpacted, administer oral stimulant or softener.
rectum impaired, stool soft
- administer bisacodyl or phosphate enema (rectal stimulant)
- once disimpacted, administer oral stimulant or softener.
rectum empty, not dilated
- exclude intestinal obstruction
2. administer laxatives as necessary, consider adding oral fleet (15mL for 3 days), as needed
rectum empty and ballooned
- give high fleet enema (phosphate enema) over several days until constipation resolves.
A. If colic is present then:
- reduce any stimulant and give an osmotic agent or softener (forlax/lactulose)
B. If colic is absent then:
- increase with stimulant laxative +/- softener
Advice on prevention of constipation
- Compliance in taking laxatives, as long as on opioids to prevent opioid-induced constipation.
- Encourage fluids generally, fruit juice and fruit specifically.
- Optimise patient’s existing laxative regimen
- Educate patient and caregiver on how to monitor bowel habits.
How is intestinal obstruction classified?
- Upper versus lower GI tract obstruction
- Mechanical versus functional
- Complete versus incomplete
Differences between upper and lower GI tract obstruction
- People with upper GI tract infection tend to vomit in large amounts, while those with small GI tract infection in small amounts.
- Abdominal distension is present in lower GI tract infection, but absent in upper GI tract infection.
- Constipation is an early feature of lower GI tract infection, but a late feature of upper GI tract infection.
- Anorexia is an early feature of upper GI tract infection, but a late feature of lower GI tract infection.
- Abdominal pain can be colicky, and is a common feature of both.
Approach to measurement for intestinal obstruction (potentially operable)
A. consider stenting if:
- Intestinal obstruction is an isolated case
- patients do not have rectal tumours
B. complete intestinal obstruction
- pain relief with opioids (morphine + anticholinergic agents like hyoscine, give buscopan if colic)
- for patients with nausea/vomiting: trial haloperidol, if not consider NGT or octreotide for high-dose vomiting.
- prokinetics may be contraindicated due to risk of perforation
